The invention relates to a laser amplification system having one or more solid bodies made of laser-active materials which are arranged in a radiation field, and which are optically pumped by means of pumped light sources, laser diodes being preferably used as the pumped light sources.
Various embodiments of laser systems of the above-mentioned type are known. These systems are usually formed by utilizing an optical cavity or resonator as lasers. In this case, to attempt to meet the respective requirements, specifically a good overlapping between the pumped beam and the laser beam, an efficient cooling of the lasant material and a high beaming quality, different arrangements are provided. However, usually the simultaneous optimizing of all system characteristics, which is important for such a system, is not achieved. Thus, a laser is known, for example, from U.S. Pat. Nos. 4,785,459 and 4,837,771 in the case of which the beam is reflected back and forth in a zigzag-shape between the boundary surfaces of a crystal block. Laser diode arrays are arranged in each case at the impinging points of the beam, by which laser diode arrays the material is optically pumped. Although this results in a good overlapping of the pumped beam and the laser beam, it impairs the optimal cooling of the pumped points.
Furthermore, a laser amplification system is known from European Patent Application 0 632 551 A1 in the case of which the pumped beam is guided several times to the center point of a small plate made of a lasant material which has a small thickness relative to the diameter in order to carry-off the formed heat as fast as possible and to therefore minimize the temperature of the small plate. However, the latter objective is only achieved in this manner to a limited degree because, in the case of this arrangement, the whole pumping output is absorbed in a very small volume range which, corresponding to the product of the surface of the focal point and the thickness of the small plate, typically has a size of from 0.1 mm.sup.3 to 0.5 mm.sup.3.
It is an object of the present invention to avoid the above-mentioned problems and to provide a laser amplification system in which the above-described system characteristics are optimized simultaneously and which, in addition, permits a compact construction and is designed such that it is suitable for mass production at reasonable cost.
This object is achieved according to the present invention, by a laser amplification system having a lasant solid-state material which is pumped by pumped light sources. One or more pumped beams is guided via mirrors or other optical aids such that each individual pumped beam is focussed several times on different points of the solid-state material, the latter being present in the form of a cohesive or separate solid body which are designed such that the pumped beam is absorbed only in the focal region whereby the latter are optically pumped. The laser beam is deflected and guided such that it irradiates through all these focal regions and is amplified in this manner. Advantageous further developments are described herein.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.